quadratic_time.py 文件源码

def k_multiple(self, X):
        """
        Efficient computation of kernel matrix without loops

        Effectively does the same as calling self.k on all pairs of the input
        """
        assert(X.ndim == 1)

        sq_dists = squareform(pdist(X.reshape(len(X), 1), 'sqeuclidean'))

        K = np.exp(-(sq_dists) / self.scaling)
        return K